8/12/2019 Gas+sampling+valve

1/5

Revisions: First Edition: 2002-04-16

No. Date Pages No. Date Pages

A H

B J

C K

D L

E M

F N

G P

Wereserveallrightsinth

isdocumentandintheinformation

containedtherein.

Reproduction,useordisclosuretothirdparties

withoutexpressa

uthorityisstrictlyforbidden.

@

ABB2002

BA Power Transformers

Product InformationIssuer: PTPT A. Lindroth 1ZBA 4694-102Author: PTPT/GD W. Klein 2002- 04- 16, Page 1 of 5

Replaced:

Operating Instructionfor Gassampling ZG1.2 EMB

List of Content

1 APPLICATION-------------------------------------------------------------------------------------------------------2

2 MODE OF OPERATION-------------------------------------------------------------------------------------------2

3 ASSEMBLY (FIGURE 1, FIGURE 3)---------------------------------------------------------------------------2

4 FILLING THE GAS SAMPLER (FIGURE 2)---------------------------------------------------------------------------3

5 GAS SAMPLING (FIGURE 2)-----------------------------------------------------------------------------------3

6 FUNCTIONAL CONTROL OF BUCHHOLZ RELAY (FIGURE 2) --------------------------------------4

7 TECHNICAL DATA-------------------------------------------------------------------------------------------------4

8/12/2019 Gas+sampling+valve

2/5

BA Power Transformers 1ZBA4694_1022002-04-16

Revision No. Page 2

Operating Instructionfor Gassam lin ZG1.2 EMB

1 Application

The gas sampler serves to sample gas collected in the Buchholz relay. It allows sampling of gas on ornear the transformer at normaloperating height. The gas sampler offers the following benefits:

- Shorter or no transformer downtimes at all after signalling of gas accumulation in the Buchholz relay.

- Enhanced safety during gas sampling.

- Easy operation.

2 Mode of operation

Through a tubing the gas collected in the Buchholz relay is pressed downwards to the gas sampler bythe oil in the conservator. Therefore, correct operation of the gas sampler requires that the oil level in theconservator is at least 100 mm above the highest point of the tubing (Figure 3). By operating the taps ofthe gas sampler in accordance with these instructions (see Items 4-6), the gas sampler is filled first withoil to the required level. Once the upper switching system of the Buchholz relay has responded, the relay

gas is collected in the gas sampler as described in these instructions (Item 5) and the relay is again filledwith oil to the required level. Then the relay gas can be analysed via the gas outlet tap by means of aanalyzer or sampled for laboratory analyses by means of a gas sampling cartridge or similar equipment.Gas sampling or testing is done as usual by screwing the respective devices on the threaded (R 1/8)gas outlet tap (cf. procedure for the test valve of the Buchholz relay).

The gas sampling process can be interrupted by closing the gas outlet tap.Once the gas has been drained, the tubing and the gas sampler will be filled again with oil.

3 Assembly (Figure 1, Figure 3)

Fit the enclosed seal (2) and screw the supplied screw-type link (1) onto

the test valve (3) of the Buchholz relay (Figure 1). Then run out the tubingand connect one end to the Buchholz relay using the olive.

Fasten the tubing by means of suitable clamps not included in the scopeof supply. Over a max. length of 1.2 m the tubing can be laid with aminimum gradient of 15, provided the remaining tubing length runsvertically.

Connection of the tubing to the gas sampler is also by an olive. Tighten the tubing at a max. torque of 15 Nm(Figure 3).

The gas sampler itself is mounted on a straight vertical surface at a level of approx. 1.4 m above floor level bymeans of two M8 screws.

Figure 1: Test valve connection

8/12/2019 Gas+sampling+valve

3/5

8/12/2019 Gas+sampling+valve

4/5

BA Power Transformers 1ZBA4694_1022002-04-16

Revision No. Page 4

Operating Instructionfor Gassam lin ZG1.2 EMB

6 Functional control of Buchholz relay (Figure 2)

Check the response of the Buchholz relay to gas accumulation as follows:

Unscrew the sealing cap of the gas outlet tap (2).

Screw the test pump onto the gas outlet tap.

Open the gas outlet tap (2).

Pump air into the gas sampler until the upper switching system of the Buchholz relay responds (gasaccumulation). Close the gas outlet tap.

Unscrew the test pump.

Unscrew the sealing cap of the oil outlet tap (3).

Open the oil outlet tap and collect the oil coming out in a suitable container.

Close the oil outlet tap when the oil level becomes visible in the inspection glass (4).

Screw the sealing cap onto the oil outlet tap.

Open the gas outlet tap and let the air pumped in escape.

Close the gas outlet tap as soon as the gas sampler is filled with oil to the required level and oil comes out

of the tap. Screw the sealing caps onto the gas outlet opening. To ensure correct function of the unit it is essential

that the sealing caps are screwed on.

Once the gas sampler is filled with oil to the required level and the inlet tap is open, the unit is ready forservice.

7 Technical data

Max. dimensions: Height 130 mmWidth 95 mmDepth 82 mm

Gas analyzer connection: R 1/8(gas outlet opening)Oil outlet opening: R 1/8Tubing dimensions: dia. 6x1 copper tubingWeight without tubing: 2.2 kgViscosity of transformer oil: max. 1100 mm/sTemperature of Transformer oil: -25C to +80C

Ambient temperature: -45C to +55C

8/12/2019 Gas+sampling+valve

5/5

BA Power Transformers 1ZBA4694_1022002-04-16

Revision No. Page 5

Operating Instructionfor Gassam lin ZG1.2 EMB

Figure 3: Gas sampler